RAJASTHAN PMT Rajasthan - PMT Solved Paper-2002

  • question_answer
    In a circuit 20\[\Omega \] resistance and 0.4 H inductance arc connected with a source of 220 volt of frequency 50 Hz, then the value \[\phi \]is:

    A)  \[{{\tan }^{-1}}(4\pi )\]                

    B)         \[{{\tan }^{-1}}(2\pi )\]

    C)  \[{{\tan }^{-1}}(1\pi )\]                

    D)         \[{{\tan }^{-1}}(3\pi )\]

    Correct Answer: B

    Solution :

    \[\tan \,\phi =\frac{\sqrt{{{Z}^{2}}-{{R}^{2}}}}{R}\] \[\begin{align}   & =\frac{\sqrt{{{R}^{2}}+{{(2\pi nL)}^{2}}-{{R}^{2}}}}{R} \\  & =\frac{2\pi nL}{R} \\  & =\frac{2\times \pi \times 50\times 0.4}{20}=2\pi  \\ \end{align}\] \[\phi ={{\tan }^{-1}}(2\pi )\]


You need to login to perform this action.
You will be redirected in 3 sec spinner